1. Field of the Invention
The present invention relates to a security system and method for a PnP (Plug and Play) device, and particularly to a security system and method that locks and/or unlocks at least one PnP device coupled to a network client through a network system.
2. Description of the Related Art
With the convenience of movable media, the data storage, backup and transport of computer information can be easily accomplished. However, the computer information that should be kept confidential can be easily leaked out by an unsecured movable medium.
Currently, the most popular movable medium is a storage device that adopts USB (Universal Serial Bus) as a communication interface. The write-protection capability of a USB storage device is performed in a hardware manner, for example, the switch of a USB storage device can be manipulated to protect the USB storage device from being written. However, users can also disable the write protection capability of a USB storage device by the switch. The way of protecting the USB storage device from being written in a hardware manner is not a reliable solution, and there is no guarantee for the secrecy of the computer information.
U.S. Pat. No. 6,463,540 discloses a securing method for computer bus devices, such as USB devices. FIG. 1 shows a diagram of the structure of a computer with a peripheral device according to the U.S. Pat. No. 6,463,540. As shown in FIG. 1, the entire computer system includes a computer 10 and a peripheral device 20. The computer 10 comprises a bus 11 to connect the peripheral device 20, and a filter driver 12 to transmit the owner identification recorded in the computer 10 to the peripheral device 20 on the bus 11.
The peripheral device 20 comprises a connection means 21 to connect the peripheral device 20 to the bus 11, a storage 22 to store the identity of the owner of the peripheral device 20, a state storage 23 to store the information representative of the locked or unlocked state of the peripheral device 20, and a memory 24 to store the information received on the bus 11 from the computer 10. The peripheral device 20 also comprises a CPU 25 acting as a comparator to compare the identity stored in the storage 22 and the owner identification received from the computer 10. If the identity of the peripheral device 20 conforms to the owner identification of the computer 10 and the state of the device 20 is unlock, the device 20 can be accessed by the computer 10.
However, in the U.S. Pat. No. 6,463,540, the peripheral device has to store the owner information and the state information thereof, and it must set up an additional processor to carry out the corresponding comparison procedures. In addition, the purpose of the conventional security method is to protect the information stored in a peripheral device instead of securing the computer information from illegitimate access. Therefore, the security of computer information between the computer and peripheral devices is still a major task to be reformed.